Definition: what “pip value” means
“Pip value” is the money amount (in a chosen reference currency) you gain or lose when the quoted exchange rate moves by one pip, assuming all other inputs stay constant. The word “pip” stands for “percentage in point,” but in modern FX practice it is usually treated as a fixed decimal step for the quoted price.
In many calculators, the result is expressed in the account currency. The phrase “USD Reaction” can be understood as: express the pip value as the reaction amount in USD (or convert it so the outcome is measured in USD). Because “USD Reaction” can mean different conventions depending on a provider, you should treat it as a definition of the output currency rather than a guaranteed platform feature.
Mechanics: step-by-step pip value model
A broadly applicable model has four parts: (1) pip size, (2) position size, (3) base pip impact, and (4) currency conversion.
1) Determine pip size from the quote format
Most major FX quotes are written with 4 or 5 decimals. A common convention is:
- If the quote has 4 decimals (e.g., 1.2345), then 1 pip = 0.0001.
- If the quote has 5 decimals (e.g., 1.23456), then 1 pip = 0.00010 (the “pip” is one tick group; some vendors also label a smaller tick as a “pipette”).
Assumption for examples below: we use a 4-decimal pip step of 0.0001 unless stated otherwise.
2) Convert pip size into a price-change amount for the instrument
For a forex pair quoted as BASE/QUOTE (base currency first, quote currency second), a price move of one pip changes the exchange rate by:
- ΔRate = pip_size
So the base-currency value change per unit of base exposure is approximately:
- ΔValue in quote currency per 1 base unit ≈ pip_size
A clearer way for practitioners is to start from the position size.
3) Use lot size to scale the pip move
Let:
- Lot size = L (in “base units”)
- Pip size = p
Then the notional base exposure is L units of the base currency. A one-pip move changes the quote-currency amount by approximately:
- ΔQuote ≈ L × p
This “per pip” quote change is the core quantity. It ignores fees and assumes the quote pip step applies to the instrument exactly.
4) Express the result in “USD Reaction” (output currency)
To express pip value in USD, convert the computed quote-currency change into USD.
- If the computed ΔQuote currency is USD already, then pip value in USD is simply ΔQuote.
- If not, you apply an FX conversion.
Let C be the currency of ΔQuote. You need a USD conversion rate that is consistent with the direction:
- If you have a rate that gives USD per 1 unit of C (USD/C), then:
- Pip value in USD = ΔQuote × (USD per C)
- If you instead have C per USD (C/USD), invert it first:
- Pip value in USD = ΔQuote ÷ (C per USD)
This conversion step is where many mismatches happen: providers may display different “reaction” conventions, but the math always requires a clearly defined direction.
Evidence or example: compute pip value across account currencies
Below are numeric examples. Since there are no live prices here, the conversion rate is an assumption used only to illustrate the mechanics.
Example A: Quote currency equals USD
Suppose an instrument is quoted as EUR/USD (base EUR, quote USD) with 1 pip = 0.0001. Assume:
- Lot size L = 100,000 EUR (a common “standard lot” assumption)
- Pip size p = 0.0001
Then the one-pip change in quote currency (USD) is:
- ΔQuote ≈ L × p = 100,000 × 0.0001 = 10 USD
So the pip value in USD (your “USD Reaction” output) is 10 USD per pip, under these assumptions.
Example B: Quote currency is not USD, convert to USD
Suppose an instrument is quoted as GBP/JPY (base GBP, quote JPY), and you want pip value in USD (USD Reaction). Assume:
- 1 pip for a JPY-quoted pair uses p = 0.01 (common convention when quotes are written with 3 decimals; pip = 0.01)
- Lot size L = 100,000 GBP
- Then ΔQuote in JPY per pip:
- ΔJPY ≈ L × p = 100,000 × 0.01 = 1,000 JPY